The present invention is directed generally to a method and apparatus for sensing the amount of moisture on a surface and more particularly to a method and apparatus for sensing the amount of liquid chemicals on the applicator roller of an agricultural chemical applicator.
The application of liquid chemicals in the form of insecticides, for example, to crop plants is an essential part of successful modern farming. Because of the large quantities of chemicals applied, a significant financial savings can be achieved by maximizing the effectiveness and efficiency of the application process.
In one type of applicator, the liquid chemicals are dispensed onto an elongated roller adapted to contact crop plants directly as the applicator implement is moved across a field. A primary advantage of these applicators is that all of the liquid chemicals are applied to the leaves of the crop plants with none of the chemicals being scattered into the air or onto the bare ground between crop rows.
It is a problem, however, to adjust the dispensing rate of the chemicals onto the roller so as to maintain the roller surface moist with liquid chemicals while at the same time preventing an excessive buildup thereon which would result in waste. But in order to properly adjust the dispensing rate, it is essential to be able to sense the amount of liquid chemicals on the roller at a given time.
Accordingly, a primary object of the invention is to provide an improved apparatus and method for sensing the amount of moisture on a surface.
Another object is to provide a moisture sensing apparatus and method adapted to continuously sense the amount of moisture on a rotating roller.
Another object is to provide a moisture sensing apparatus and method which is adapted to prevent erroneous readings resulting from variations in the moisture level at axially spaced locations on the roller.
Another object is to provide a moisture sensing apparatus and method wherein a signal indicative of the moisture level on the roller is compared to a predetermined value corresponding to a desired moisture level for the roller, thereby providing an indication of whether additional moisture is to be dispensed onto the roller.
Another object is to provide a moisture sensing apparatus and method adapted for sensing the amount of liquid chemicals on the applicator roller of an agricultural chemical applicator.
Another object is to provide a moisture sensing apparatus and method which is simple in construction, durable in use and efficient in operation.